Apparatus for seasoning and granulating acidulated phosphate



June 1948. W, J, SACKETT v -2,442,513

APPARATUS FOR sEAsoNING AND'GRANULATING ACIDULATED PHosPHATE Filed Nov. 11, 1943 5 Sheets-Sheet 1 [USA CRE TT Jun@ l, 1948. W J, SACKETT l 2,442,5l3

APPARATUSIFOR SEASONING AND GRANULATING ACIDULATED PHOSPHATE Filed NOV. l1, 1943 1 5 Sheets-Sheet 2 a mi' (/Q SAC/f5 TT www June 1948. W, J, SACKETT 2,442,513

APPARATUS FOR SEASONING AND GRANULATING ACIDULATED PHOSPHATE Filed NOV. ll, 1943 Y 5 Sheets-Sheet 3 .AM/ TER L/. SQCKETT .lune l, 1948. W, J. SACKETT l 2,442,53

APPARATUS FOR SEASONING AND GRANULATING ACIDULATED PHOS'HATE Filed Nov. ll, 1943 5 Sheets-Sheet 4 l2. jme/MM' ALTE/ 6A CKETT June l, 1948.

APPARATUS Fon sEAsoNING AND GRANULATING ACIDULATED PHosPHATE Filed Nov. 11, 1945 wf .1.l sAcKETT 2,442,513

' 5 Sheets-Sheet 5 Patented June 1, 1948 ...UNIIED .SIIAlES .APPARATUSFOR sEAsoNlN-AND T@RAKU-- 'i LATIN G' ACIDULATED PHOSPHATE 'Walter J. :'Sackett,;'=BaItiin0x-'e,.` ...assigner to ...The A.; J. y,Sackettat.Sons Companygaltimore, .1.Md., a ccrporatonof Maryland fiApplicationNovember 11, 1943, Serial N o. 5035864 3 Claims. (Cl. 23e-259.2)

While the inventiva idea @originatedfandghad its development in connection with theaacidulatieni-'oil:phosphatez'rockuit-fis-broadly-applicable wherever a self-sealing uid is formedinto. a moi/ingrV cake: ofvwhiohf .the forward@ end :porti-on is more or less continuously separated andi removed,as.:the. Jnishedpfpl'cductV or to be .further treated.

According-itc.. lthe exstinefpra'ctice in-"fthenproduction. foifaidulatedflphosphate; .theA phosphate:

rockf.--is;.=pulverlzedfiand; mixed: :with acid; satisfactoryl formulas.: as to. strength: and: proportions being :wel-known This .zfm-ixing-` may be merformedfirr asbatolnmixer prin a'mxerfintawhich sulpl'luric` acid. andzfneiy dividedzphosphate rock.

areffed -eontinuouslyf and't-.f-rcrn.WhichiJahre` resultingr'mixtu-re: :is f.. discharged continuously. With either typemffmixenrthe product/.fisv a liquid 1referred rto.T as: slurryofgpa-V varying-consistency resembl-ing` that: cfepancake batter. According :to

existing .practice, the 'mlixer. delivers: directly .into a concrete. pit` or: deniin .which the z-materialaccumulatesuntil fthe receptacle koridenyis filled to a convenient level.

^ 1. The: Y mixing; processiV s. then tdscontinued and ther accumulated material .isF removed. andplaced in storagetzbins ',Elrisfremoval of-.the:=.material from the den is performed from thetopfby crane buckets or through. a removableesideby fmechanical -v 'ercsavatorsz` or: byJ-.hand 's excavation. 'While thevrmaterial ist.thllsiaccumulatingl fin the iden: .rit becomesr partialiy seasoned and hardensx-or sets andI fmust: be brokenfycomingf: out' fin chunks.: or

pieces; of varying fsizetwhich! must be 4u'rtller reof rits. tendency;ftoazattaclcljthebaat-matenal;y also' the operation of renmcingtat intervals-the=aocu nmlation; ofhardeneinateriahrcm; thedenf .or binflstan :expensive:operationtnotlinvolyed .in-the newa:rne.tl-11: d,` .urthert .under ...the-.conditions prerailing in the. usecf the old apparatusandfmethodf. .the-opportunitxrfiorsthe .escape of. .the.aetive gasesf-.Whchds:themain.fp1l1`p0se. of seasoning, isl. Alimitelztras. comparedtd that .aiorded VAin and by, thetnewmethodlandzapparatus.

Theanvention relates.. to. a. -nevrand .improved methodfandf-.apparatuswhereby the, difficulties an.flhdecenciesv tIiueset` forth andl other l defects inthe old Dractceihave beenovercome.

thefpracticefof thenewfmethod 01 lDrOGeSS, using. v:the .-new.--apl &r&tusboth,of. which are` Vregardedtasffeatures; of, the-invention, the mixer is to -liestfadvantageloi.thecontinuous type, rin that itftdscharges .continunusly..,into.- a new .type of denier seasoning hin. ,Thefmixture lor slurry. as 15;.

itv comes :to the denis, .stilljliquidor vfiluid,- as.. above describedtand:"the-denL is fin .the Afornrof a deep continuouslygvmovingtchannel provided ...by .an endlessfconfveyergwhich tin `the ;preferredform of apparatusshown .is composed of QUfshaped plates, mountedy ,ons a: conveyer f chainfwhereby =the -top Hight.` ofllthe, conveyemprovldessuch ...a channel. It .is regarded: as,- .of. importance ,in .thisconnection that while. sucht-afconveyerswhich the only kind whichwcould shave. -suiiclent .capacity `for `the purposaa-cannctfbefmadexliquid .,tight, ithas Vbeen discovered that ..fthe particular liquid being treatedlisfselffsealing, so thatit does not.- escape by. ieakage-zandftherezls noflosson this account.

- .The :material tthuscomes. .to :the traveling l.den

onconveyerfln: a liquid stataand is-fpermitted to hardenztherecrrfV also becoming-.whollyor partially seasoned or neutralized by loosingthe bulk-of its activefgases. .nthe-presentlpractice; tothe details: of-ffwh-iclr thefinventionis Anot limited, ,the

- traveling-.den lsu; feet yWdeand-BO feet longand 2iachesgdeep; and :tra-wels. at. a `rate l ofl about 16 inches per minute soohattthematerialisexposed inthe: den;:ionffaesuitableueriodwhich fin. said practice oithefinrelltinn A.1s;-,ab0ut..amhour. 4.Acc ordinex; ftostheepractice. to. the, .present date, :the materialin itheidemhas been linches in depth ori-thickness. I nth'e cmpletelorwpreferred lform ofithaapna-rat-us; the;-:den is .hooded throughout lts lengthmndthe atmospherefis exhausted Afrom f the rhood-:ebeinggdrawn linzal'ound -thechannel or den mear. the .iicorjY andffwithdrawn' at successive locations spaced along itspath.

.f vrecording-3: ftorthe; ipreferredgpractice, the atmosphereethusfmithdrawn,which .isg combined airfandegasesexhausted Afrom the-,material in seasoning, is continuously washed'fand4 the-solids formed orrdepositedi fin-:the water are allowed to settle so that they may.be,,separately.4 removed and-fthetremainderaofethe ywish...Water is.re turned and reintroducedgtol thewash'ingarea. VVVIn progresses from the liquid to the solid condition'y on or in the traveling den, and at the delivery end the elongated cake formed by the hardened material, may be continuously cut loose from the den and at the same time, reduced to a condition which may be termed granular in which it can be fed to a hopper and distributed by suitable conveyers to storage bins or if suiciently,

neutralized, a result which can, when desired,

be accomplished by this apparatus, it may be imrnediately bagged for shipment.

At the time of exdenning or removal from the den, the material is so hard that in the old practice, excavating tools have been necessary, the exact degree of hardness being known-to those skilled in this art. In the practice of the invention, the material, when removed from the traveling den is of similar hardness. The turning of the conveyor-like traveling den about the end sprocket, i. e. at the forward end of the top flight of the conveyor has been found to break the material into chunks. These are however, too large for delivery to and discharge from the usual type of hopper and would require further grinding.

According to the preferred practice of the invention, the hardened material is cut from the traveling den and reduced to the desired size by means of a rotary toothed' cutter, which in the preferred form shown has its cutting edges arranged in the formlof a multiple helix, with its axis transverse to the motion ofthe traveling den, whereby continuous and uniform contact of the cutter with the material-is maintained, avoiding the shock and jar to the apparatus incident to repeated or intermittent action of the cutter. To complete the stripping ofthe den, a stationary cutter, slightly spaced, from the inside surfaces or the horizontal surface of the den may be located beyond the rotary cutter in the direction of traverse of the traveling den, other features being hereinafter described.

In the accompanying drawing, I have illustrated the apparatus of the invention in the form in which it has been developed, the same being subject to further changes of arrangement.

In the drawing:

Figure 1 is a side elevation, drawn to a minute scale, illustrating the apparatus in a general way, and partially diagrammatic, the den being broken away at two places, intermediately of its length for convenience of illustration.

Figure 2 is a transverse section'on' a similar scale taken on the line 2-2 in Figure 2.

Figure 3 is a transverse section on the line 3-3 in Figure 1, at the rear of the traveling den, showing the sump and settling tank, and adjacent parts, the settling tank being in elevation, and broken away for purposes of illustration.

Figure 4 is an elevation of the rotary cutter, the 4den and track, etc., being shown in section on the line 4-4 in Figure 1.

Figure 5 is the section at right angles to Figure 4 taken on the line 5 5 in said figure, and looking in the direction of the arrows, and illustrating the rotary cutter.

Figure 6 is fragmentary side elevation of the traveling den or conveyor. 1

Figure '7 is a horizontal section looking downwardly from the line 1-1 in Figure 6;

Figure 8 is a view similar to Figure 'l with the plates, i. e., the U-shaped den plates, removed.

Figure 9 is a fragmentary sectional plan on the line 9-9 in Figure 6, looking downwardly and showing the manner of engaging the adjacent plates one with the other to close the sides of the den.

Figure 10 is a sectional plan looking downwardly from the line ill-l0, Figure 4.

Figure 11 is a vertical section on line lI-II in Figure 10 looking in the direction of the arrows.

Figure 12 is a vertical section on the lines l2--l 2 in Figure 13.

Figure '13 is a sectional plan looking downwardly from the line I3-I3 in Figure l and in the direction of the arrows.

Figure 14 is a sectional plan looking down- Awardly from the plane indicated by line l4-i4 in Figure 1.

Figure 15 is a fragmentary side elevation of the delivery end of the conveyor illustrating the shield drum.

Figure 16 is an elevation taken from the right in Figure 15.

Figure 17 is a side elevation of the shield removed.

Figure 18 is an end elevation of the same.

Referring to the drawings by numerals: The construction shown comprises an elongated endless traveling conveyor chain l which in the formV shown includes links 2, 2 connected by transverse pins 3, the double links 2 and 2' being spaced apart and each pin 3 carrying a supporting roller or wheel 4 between the links 2, 2', whereby the upper flight of the conveyor is supported on rails 5 and the lower iiight is suspended from lower rails 6.

In the form shown, the rails 5 rest on longitudinal parallel I-beams l, being preferrably near the floor level and the rails S are in the form shown supported by combined angle irons 1 and 8 which may be suspended from beneath the I- beams 'l or supported in any suitable manner, which is no part of the inventive thought.

The upper and lower rails 5 and 6 are each two in number, forming parallel tracks, spaced as best shown in Figure 4, the spacing in the structure from which the drawings were made, being a little over 4 feet.

Referring again to Figure '7, each of the inner links 2' has secured to its vertical side toward the center of the path or track, the vertical web of an angle iron 9 which provides a flat horizontally projecting plate or lug IG on each link or any suitable proportion of the links. These plates or lugs may be described as in pairs, projecting inwardly or outwardly if preferred, from corresponding links of the conveyer chain l, and each `pair of such plates or lugs I0, and hence each pair of links 2 of each conveyer chain I. has secured to it one end of the horizontal member H of a U-shaped plate I2. In the upper night of the conveyer, the upright legs of the U at I4, project upwardly in an approximately vertical direction, with their vertical side edges i4' either in contact or in close relation as best shown in Figure 6, it being understood that the U-shaped members IZ'are in the form shown, elongated iiat plates of nearly uniform width and with their long edges parallel. Said plates being bent at the corners of the Us at !4" to form the U-shaped members described.

In the preferred form, the adjacent edges I4' of the upright portions I4 which form the legs of the U plates, are held as nearly as possible in contact by the lugs l5, see Figures 6 and 9. These lugsin lthexformY of the invention showir are@ horizontally disposed' `Withitheir greatesttrans.- verse i dimensioni vertical and 'overl'ap the fad'a-b cent :edges Mf' of the 'platesfbeing 'securedft one edge as fat: i6 fandainr fricti'onal 'engagement with the other 'adjacent .edge asfseenfin plan," ini Figure :9 at I1; the forward fend-,fof eaolriluglbeing` inclined'outwardly away'irorrn the center oi the conveyor' .or'bin' as atti 3` Lto-iimprove "the1 contact atzthe? initial;r portion; f of. the f engaging action which occursi as .eachsiipl'ateswingsf about the sprockety atl f the beginning f or `Vinitiai portionr or the n:top flight :ofthe conveyerfatlsprocket 19,11 Flgtu'el.'l Itfmay bennted: that these :clamping end ofthe topzight oi.` the conveyergl' or traveling@ den `2U5fan acidulatort, which.l is preferabl'yfor Y thecontinuousftype though: aY batch mixer or.

several ofethem could'fbeusedfwith this apparat to i lessI advantage.

The r' drawing.l indicates a=piipe. 22 `for Athe continuous. int-r'oduction.V of acid' and a chute 24 "for the continuous introduction oi? groundrphosphateroclzand-y an fair fpassage f whereby "the pulverized'r or 'groundf 'rock fis. blown into-lthe apparatus,- As-'b'othabatch mixers and-.continuous acidula'tors capable* of use with;U this apparatusl have been shown-I inf-the prior patents,` no Lspeci'c description of this unit is regardedasnecessary?' The broader scope-'ofthe invention; contemplates the use-"ofE other :reagents and for. other: solids.l p1-oe ducing.' 'alselfesealingf1lir:1uidltoi.be'v solidied into a continuous cake to 'be vfurther treated "substantially as 'herein' described. l

Treating the unit 2| fas continuously operating;

it delivers the slurry already.fdescribedlinf-a conA tinuous stream to theinitiall endwofifthe.*slowly moving' traveling iden'VA 2d; which in Ythe form i1` lustratedmov'es iniY the :direction of the JarrowA `A atthefcenterlof.zthefapparatus. Preferably. thef of the itravel'ing'denLZ 6' fand a vcasing 55 further encloses it against 'escapeoi the 'gases Sand liquid;

toward the onenend'oi"v the 'apparatusfat the "left infFigure el."

The slow motion of the'conveyer'or traveling denwhereby the .liquid is. seasoned and'solidif'ed thereon-g'hasfalready 'been described andithe most approve'dmanner of removal or` the .continuous The ycutter 39fas shown, Etain' the channelwithinthe U-shapedtvmembers. l2. formingvthe traveling-den, and it icuts-Vfromtheiforward end-f of thecakef3| which. forms in the traveling, den asbest shown in Figure 5;

In the fcrm shown, the cutter 3i] is provided' with .forwardly disposedicutting teethv 32 having chisel-like cutting edges 33; In the form shown;l

the cutter vrotates 'counterclckwise as seen fromn the `left in the `Figure *5 fandeach cutter' 32 l'is 'in the f form 'of ar plate shaped* longitudinally; aio-- proximately in the form of -a circular are; about shaft 34,- but of reducing radius; oackvvardlyj-v i. e.

oppositelyto the direetiorr'of rotation; Shaft'fS-f is "driven by an electri'cfmotor' or inf' any '-suit; 75-

6 1 able manner,-V amotor adapted toithis purpose be@ ing indicated at: 35 iin: Figure :1,4 said.- motor car.- ryingi afsmall `pulley'S 6:; which "drives: a '-bel't Aorchainfr't, which; drives-a larger pulleypr sprocket 38fon the 4rout-ter shaft 34; andfin-the'form shown;

Figure 4; the "ar-rangement*describedbeing ren ferred' to .for AVconvenience, as staggered.`

While any method of disrupting oridisintegrating 'orbrealnngnthercake at `itsiiorward endis contemplatedtitis found to be :of advantage tov -f provide a continuous engagement .of the-cutters with theadvancedend of the cake-'and asubstan'-v tial-1y uniform' engagement aat all times to avoid 1 thfshookand Vthe fharmfrulvibration-i to'the. appa ratus which would result ffrom'f uneven oir-periodic lI' cutting :Las Iif .-th'e cuttersfswereearranged in lines parallelftol'thefaxis. To this'end,l thecutter bodyA which is, ShOWIifinQtheformf of a cylinder is-so constructdas topermit thezlines 42; 43;,etc;, of' cutters'to be helicaily'arranged-"solthat.the cut-y teriaLis' substantiallyiuniformand"atleast 'continuous, theHalter-nate1 arrangement of cutting; teeth Acontributiingetoit-.he "ease'of cutting and also to the `granular form of the product;

In'theformshowmieachsline of cutters 42,` 53

` secured' lattheirrends to :diametricalib-ars `orbeams.

gvwhi'cn arel-inwurnsecured to ,the :cuttershaft 34; The'cutters32 iofveach'line mrojectfforwardly inthe fdirection ofl rotation from the -rcorrespondI ing; plated# :being'spacedA apartas fdresai'd :by

cutters .and preferably inrhelicaiL lines orapproxi mately so, lthe cuttersi-oone linesbeing cirournL frentiaily "ailigried;1 With: thespaces: of-l another iineor .the next line;

The granular .material inftherformto YWhichxit may be reduced :asfit'comes from. `the discharge endof the den is discharged-in 'any `suitable'niam tributedfinthemann'er suggested in the preamble or'anyxsuitable manrrenit 'being understood thatA the fehamgel ofuireetiorr'about 'the sm'ali. diameter, forward" sprocket. would '.break andi discharge the materiaminchunks'- which are usable butnot capable 'f of. handl-ing' asl justl described'.A .saidiV sharpi change of directiongrconstitutes-'a means for separating 'the vmateriar.intofragments',` r

Inv the form shownlthe fumes fromirthe ftralvele ing denf lleL andpreferably 'e also: -from'fth'e 'acidu latorZl arre1 -rro1rrth'ezvieinit'y` ofi. the knife' or rot-ary: cutter: are condctedfzatisuitabie points'.

by-wairi'of `risers Whichfare shown; for :example vfat 2 48,."49, and ste afmain 66; andtlater discharged; Any suitable number of risers may be empioyedi It' :muri-"loe inoted--that .ii-,hef-riser 5D lisfccnnected to'1v the-:cutiiercasine'f sl-xoW-rr'etI 5i nfFi-'gure 4-,1

and also in Figure l which knife casing leads downwardly and terminates in the chute 41. It also leads upwardly to the riser 50, also merging with the hood 55, This hood 55 extends the entire length of the traveling den, being closed at the delivery end ofthe latter, by junction with the discharge casing and at the initial end by the intake casing 56 which is closed about the delivery of the acidulator 2|.

The hood 55, preferably encloses the top and sides of the den, having its lower, horizontal side edges at 51, spaced but slightly above the floor,

the level of the two adjacent floors being indicatedat 58 and 59 in Figure 1 at the right.

The washing of the recovered atmosphere in the form of apparatus shown is performed in an inverted frustoconlcal chamber section 60, shown as depending from an upright cylindrical chamber 64 and having an upright frustoconcal dis charge section 6| from which a pipe 62 leads downwardly to the settling chamber 93 to be further described.

The upper section of the washing chamber at 64 contains a downwardly disposed atomizing nozzle 65 which is axially related to the chamber 64 and to the frustoconical sections S0 and 6|, the cross-section of the jet at 12 being approxi mately equal to the cross-section of the restricted portion of ythe chamber at 12.

A pipe `fifi, in the nature of a main, connects the risers 48, 49, and 50 and such other risers as may be found desirable Vfor the purpose of exhausting the atmosphere from the hood 55. Main 6B as shown, discharges into the two Ofi)- posite sides 65', BB" of the chamber 64, and the atomized jet 61 from the nozzle B5 has an ejector action whereby the air is drawn from both sections of the main 66 at 66 and 66", and passes downwardly into the settling or separator chamber 63, Where the liquid and the contained solids are deposited at 10, being separated from the air by suitable bailles 1|, the w-ashed air escaping through any suitable outlet as stack 13.

In the separator chamber 63, various :materials accumulated in washing the atmosphere or air and gases from the hood are deposited in solid form at 14 and the relatively pure water is drained at a higher level by a drain pipe 15,.wl1'ich discharges into a sump 16 from which the' wash water is withdrawn by a pump 11 which discharges under pressure through a pipe leading to the spray or atomizing nozzle 65.

The solids are withdrawn from the chamber 53 by way of doors 19, such removal being accomplished at suitable intervals and at times the water in the sump 16 is changed, new clear water being introduced by way of pipe 80, the saturated water being first withdrawn by way of pipe 8|, both of which in the form shown are connected to a pipe 82, which by suitable valves may be connected alternatively to a supply or to a discharge.

For convenience and conformity with the terminology which has been used in connection with this apparatus, the hood 55, the risers 48, 49, and 50 and the main 66 are referred to as a vacuum system, the fact being that an appreciable reduction of pressure below atmosphere actuaflly results from the ejector action incident to the operation of the jet 61 which being combined with the air, in the restricted area 12, and the expanding area 6| and continuing in contact there with in the chamber 63, effects very complete washing.

In operation it has been found that some of the material removed by the cutter 30 accumu a considerable amount of water.

lates on the surface 99 of the conveyor which is uppermost in the return or bottom flight. To remove this material Scrapers |00, |00', |00" have been provided as shown in Figures 10 and 11. In the form shown these Scrapers are V-shaped as seen in plan, the point of the V being opposed to the advancing conveyor and material. In the form shown the bottom edges 50|, |0|, |0|" of the Scrapers |00, etc., are at different levels the one adjacent the delivery end at IBI" being spaced upwardly from the conveyor bottom 99 by the greatest interval which is reduced by steps, the scraper |00" being closely adjacent the conveyor. These scrapers are preferably located over the discharge A41, or in discharging relation thereto.

Due to change of operating conditions as the quantity of mixture fed to the den or the speed of the latter or other conditions, it is desirable to vary the vacuum in different parts of the den, particularly to decrease the vacuum near the initial end of the den, to eliminate any tendency to withdrawal, by the vacuum, of material which would otherwise be formed into the cake.

For this purpose damper |09 in riser 48 and ||0 in riser 49 have been provided. As shown, these are hand operated and suitably held in various positions of adjustment.

It is also noted that it is found advisable `to make the stationary scraper or cutter 30' which ts inside the U-shaped member |4, also of U shape, fitting the sides and bottoms of the U-shaped member I4, otherwise the cake tends to accumulate therein.

It is further of interest that the commercial acid now obtainable, or that ordinarily available at figures suitable to this use, is weak or contains To have the cake relatively dry at the point of removal so that it is readily reduced to granular form, it is found helpful to heat the mixture or material as introduced into the den or at the discharge end, the heating of the material at other points in its path having the same tendency, but being regarded as somewhat less desirable. For the purpose stated, flame heaters are shown at the initial end of the den at |05, acting on the material as it comes from the mixer and at the discharge end at |06, other locations of the heaters and other heating means being within the broader conception of the invention.

It is also of importance that the undesirable fluorine content of the product is reduced by heating the material particularly at the discharge end as or after it passes the cutter.

To overcome the tendency of small fragments of the cake separated at the discharge end' of the traveling den or conveyor channel or chamber to pass downwardly or drop between the U-shaped plates I4 where the contact between the edges I4 of said plates is broken as this conveyor rotates from the upper to the lower flight, about the forward sprockets Z0 a drum-like form of shield has been devised. In the absence of this shield or other means for intercepting these particles a large part of them would lodge on the top surface of the bottom or return flight of the yconveyor whereby a considerable portion of the material would avoid the delivery shute 41 being carried back to a location beneath the initial end of the upper flight.

This shield |28 in the preferred form shown, while it may be referred to as a drum is to best advantage of angular cross section being coaxial :with the shaft on.

cross section, each side 1300i the drum being inv the preferredform shown, tangent to the peripheral arc |3| between the corresponding sockets |25 or notches of the sprockets 2B.

The drum |28 in the formjshown is supported on gandr carried by the sprocket .shaft |25,jthe drum sides l|30 extending from-one sprocket to the other, ,the ends of the drum sides orfxside plates `|30 beingnotched or rabbetedat |34 to admit thelugs onwhich :U-shaped channel plates .I4 aresupportedand by whichthey are vconnected. to the conveyor chainy .-In the,formvshowntheshaft'125 carries two drumsupports |32 eachof which is ina radial plane of the shaft |25 and secured thereto. These supports |32areshaped according tothe cross section of the drurn, in. the. form shown -being hexagonal and the `drum sides.. |39 are Vsecured to the supports forming the 4hexagonal :drum |28.

vThe supports |32 are as shown spaced-inwardly' from the sprockets 20.

In operation vthe shield |23 rotates withthe sprockets 20 and with the conveyor and channel ,platesi i4, the vertices |`35vof fthe hexagonal shield closing the openingsi 1&5 betweenzbottom portions M" otplates; i4 asntheybreakapart in rounding the sprockets 2e. "In :this way leakage of the fragments through the bottom of the channel conveyor is prevented, all or practically all the material freed from the conveyor being delivered through and by way of the shute 4l.

It may be noted that in addition to the rotary cutter 3B, a iixed cutter 30 is also desirable, whereby the adhering material is inally removed from the plates |2, particularly the transverse portion Il, though the cutter may be U-shaped to t each entire plate if desired.

While a continuous acidulator or mixer is preferred for feeding the apparatus `of the invention, it is conceivable that one or more batch mixers may be arranged to feed it for a period of time or successive periods in which the supply of fluid to the apparatus would be continuous.

The method or process will be fully understood from the preamble taken in connection with the description of the apparatus, the operation of which is believed to have been made clear.

Important accomplishments of the invention are the continuous formation of a cake from a continuous supply of fluid acidulated phosphate rock, supplied in the form of the usual slurry with the continuous abrasion of the forward or hard end of the cake, whereby continuous production of granular acidulated phosphate is attained, it being however, feasible, if desired to merely break the cake at the delivery end of the den.

It is further of importance that the new process and apparatus eliminates the idle period of the mixing plant, and operators or attendants with consequent saving of time of both and a further increased output from the plant which results from elimination of idle periods necessary for removing the hardened material from the stationary den in which it has according to the prior practice been deposited.

A further important accomplishment is the elimination of theY expense@ of `excavation"from -theden and of the grindingerotherureductiqn of the sizeof the-particles afterexcavation.

'Another and stille-furthery accomplishment is the continuous recovery of the active ,ingredients from the atmospherewhichsurrounds the vlocation of seasoning, wherebypu-reair --is discharged, lthe said ingredients are saved andcontamination of the atmosphere is avoided.

- Having lthus described afsingle 'example of the `application-oi. my inventionwhich 4is subject,` to a fdegree of'variation in accordance withthe ability Vof those familiarwith the correspondingpractice, and also-having described an apparatusused and 'ibundpractical in-making acidulated phosphate accordance with--myinventicm what I- claimas new and desire to secure by Letters Patent ;is:

`1.An apparatus for treating a solidiable fluid `fertilizer material which comprises, an ,endless conveyor having a long -substantiallyhorizontal upper flight composed of a plurality of juxtaposed individually rigid members each having a bottom and upstanding sides, linked chains having rollers on horizontal spindles at the link joints, Asaid membersbeing mounted on the links above the roller spindles, said members -being Vmounted `on said chains to form a continuousA longitudinally rollers-ride to supportzthe channelin itshorizontal `night, means to; discharge fluid material vinto ,the

.conveyor atthe beginning of the ,horizontallight means at the other end of said iiight to break up the material which lhas solidified during its passage from one end to the other of said flight, sprocket wheels for said chains having roller receiving sockets therein at the delivery end of said flight around which the conveyor passes and bends separating the adjacent edges of the channel members longitudinally, both at their sides and bottom, and breaking the continuity of the channel, said sprocket wheels having therebetween angled plates, the angle of the plates and the roller spindles lying in a common radius of the sprocket, the plates extending above the roller sockets and adjacent and under the open spaces between the bottoms of the conveyor members to render continuous the bottom of the conveyor as it rounds said sprocket wheels, and to keep the material from falling to the lower run of the conveyor.

2. An apparatus for treating a solidiable fluid fertilizer material which comprises an endless conveyor having a long substantially horizontal upper flight composed of a plurality of juxtaposed individually rigid members each having a bottom and upstanding sides, linked chains having rollers on horizontal spindles at the link joints, said members being mounted on the links above the roller spindles said members being mounted on said chains to form a continuous longitudinally open channel in the horizontal flight in which each member contacts the adjoining member at the longitudinally extending edges of each respective member, and the contacting edges of adjacent members are in the same vertical plane as the spindles of said rollers, tracks on which the rollers ride to support the channel in its horizontal flight, means to discharge iiuid material into the conveyor at the beginning of the horizontal iiight, means at the other end of said flight to break up the material which has solidified during its passage from one end to the other of said ilight, sprocket wheels for said chains having roller receiving sockets therein at the delivery end of said ight around which the conveyor passes and bends separating the adjacent edges of the channel members longitudinally, both at their sides and bottom, and breaking the continuity of the channel, said sprocket wheels having therebetween angled plates, the angle of the plates and the roller spindles lying in a common radius of the sprocket, the plates extending above the roller sockets and adjacent and under the open spaces between the bottoms of the conveyor members to render continuous the bottom of the conveyor as it rounds said sprocket Wheels, and to keep the material from falling to the lower run of the conveyor, means to rmly support the return flight of said conveyor and a plurality of scrapers projecting into the return ilight of the conveyor, each successive scraper in the direction of travel of the conveyor being spaced nearer to the inverted bottom of the conveyor members, the nal one being closely adjacent thereto to scrape the same clean, so that a tight channel may be presented for the receipt of further uid material.

3. An apparatus for treating a solidiiiable fluid fertilizer material which comprises an endless conveyor having a long substantially horizontal upper night composed of a plurality of juxtaposed individually rigid members having a bottom and upstanding sides, chains on which said members are mounted, in the horizontal ight said members being mounted on said chains to form a continuous channel, means for driving said con- 12 veyor, material feeding means above the upper flight, at the beginning end, heating means between the material feeding means and the upper flight of the conveyor directed in the direction of movement of the conveyor to heat the material on the side that will then contact the sectioned channel conveyor.

WALTER J. SACKE'I'I.

REFERENCES CITED The following references are of record in the le of this patent:

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